Although utility handlamps are well known to the art, such devices as are customarily provided rarely if ever combine desired features of use with simplicity and ruggedness of design. Where such lamps are rechargeable in nature and charging means are provided, similar drawbacks exist in the charging means.
Where focus adjustment of an emitted light beam is provided, this is customarily carried out within the lamp housing by allowing adjustment of the distance between the focal point of a parabolic reflector body and the incandescent filament of a light source. This may be accomplished either by moving the reflector body or by moving the light source and, in either case, such movement is conventionally imparted by lever means, slide means, or cam means. These arrangements generally do not provide a smooth action or precise focus control. In addition, these arrangements tend to be rather complex, with a plurality of extra parts being required for this purpose.
Utility handlamps which provide means whereby the path of travel of an emitted light beam may be varied in desired directions of angularity are also known to the art. Customarily this has been accomplished by mounting a luminaire "head" including light source means, reflector means and light transmitting means in a manner such that the said luminaire head may be rotated or swiveled. Again, this requires a plurality of extra parts and, in some cases, premature failure of the device caused by fatigue of moving parts or wires may result. In addition, such arrangements are not easily mounted for hands-free operation on a belt member.
Charging arrangements for such lamps either include plug-and-receptacle arrangements or wiping contact arrangements. The first of these is failure prone because of the vulnerability of male portions of the arrangement to breakage and of female portions to entry of dirt, which may become compacted therein. Wiping contact arrangements as conventionally provided, on the other hand, are vulnerable to loss of electrical contact, particularly under conditions of vibration of the charging means.
The need for handlamp and charging apparatus which overcomes the drawbacks cited above is particularly evident in certain public safety fields, particularly firefighting. Such apparatus must be focusable to provide a beam which can penetrate dust or smoke, be operable either hand-held or clipped to a belt or pocket, and also be capable of illuminating an overhead area while resting on a supporting surface and where the beam should be adjustable through varying directions of angularity. Such a lamp must be rugged and reliable, with simplicity of design and a minimum of moving parts providing ease of maintenance and use.
In addition, such a lamp should be rechargeable, and the charging arrangement should be easy and quick to use. It is essential that good electrical contact between charging means and the battery of the lamp be maintained, when engaged by the user, through varying conditions which may, for example, include extreme vibration.